Synthesis and epoxy curing of Mannich bases derived from bisphenol A and poly(oxyalkylene)diamine

✍ Scribed by Jiang-Jen Lin; Shiau-Feng Lin; Tso-Ting Kuo; Feng-Chih Chang; Feng-Po Tseng

• Publisher: John Wiley and Sons
• Year: 2000
• Tongue: English
• Weight: 194 KB
• Volume: 78
• Category: Article
• ISSN: 0021-8995
• DOI: 10.1002/1097-4628(20001017)78:3<615::aid-app170>3.0.co;2-n

✦ Synopsis

A family of Mannich bases were prepared from the reaction of 2,2-bis-(4hydroxyphenyl)propane (bisphenol A or BPA), formaldehyde, and poly(oxyalkylene)diamines at 1 : 1 : 1 or 1 : 2 : 2 molar ratio. By varying the molar ratio of bisphenol A to amine and the chemical structures of poly(oxyalkylene)diamines, a series of products with multiple functionalities of primary/secondary amines, phenols, and poly(oxyalkylene) were prepared. The curing profiles of these products toward the diglycidyl ether of bisphenol A (DGEBA) were examined by a differential scanning calorimeter (DSC). The physical properties of these cured materials were correlated with the chemical structures of the Mannich bases. Compared with the poly(oxyalkylene)diamines, the built-in phenol moiety in Mannich bases accelerated the curing rate. Both amine and phenol functionalities could be reactive sites toward diglycidyl ethers in a step-wise fashion under catalytic (triphenylphosphine) and different temperature conditions. Furthermore, the cured polymers demonstrated improved properties including tensile and flexural strength in comparison with those cured by the corresponding poly(oxyalkylene)diamines.